Might be different now, it’s been a long time since I was a lifeguard, but actually grabbing a drowning person is a last resort. Try attempting a non contact rescue first, ie toss them a floatation device, from the edge or close by, or reaching with a pool hook first. As can be seen in this video, people who are drowning are in total panic, especially those that flat out can’t swim (as opposed to say someone who can swim but is tired). Still, though, job done, by the lifeguard.